• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1181-1186
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• 2013

Mobile network has become an essential tool for mutual communications, so a survey research published that most of the smartphone users use Mobile Instant Messenger every day. In this paper, we developed a wire-wireless integrated web messenger that can be used in various platform of mobile devices and desktop computer for communicating between users of some companies. We defined a multi-organization as several independent companies. Our web messenger was developed for communicating of users of a multi-organization. So one of functions of our web messenger is to restrict access to some particular departments in each company for the security of their company. Developed web messenger worked reliably from variety of web browsers on most of platforms such as android, iOs and desktop computers.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.41-47
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• 2007

The first geostationary satellite made by Korea, COMS, has the three different payload ; Meteorological sensor, Oceanographic sensor and Ka-band communication payload. There are Meteorological & Ocean Data Communication Subsystem(MODCS) and Telemetry, Command and Ranging Subsystem(TC&R) as other RF radiation sources. MODCS transmits and receives Meteo and Ocean measurement data from/to earth using L-band and TC&R using S-band. The Ka-band communication payload will provide high-speed multimedia services and communication services for natural disaster such as prediction, prevention, and recovery services in the government communications network.Ka-band beacon is for the earth antenna pointing and the experiment of rain fading. This paper gives the analysis results about the mutual radiation effect on Ka-band communication payload, Ka-band beacon, MODCS and TC&R. Up/Down link power and coupling factor including the geometrical position and distance of antenna, filter rejection and degradation factor due to the different polarization are considered. The results show MODCS and TC&R are compatible for Ka-band communication payload and Ka-band beacon does not interfere with MODCS and TC&R normal operation.

• The Journal of Korean Society for School & Community Health Education
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• v.1 no.1
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• pp.95-106
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• 2000

The purpose of this study was to be of use for the preparation of more desirable sex education system at elementary school, by making content analysis of the current textbooks related to sex education and surveying what opinions the persons concerned had about it. The purpose of this study were as follows; Elementary school textbooks were analyzed to find out what kind of sex education was included in them. And questionnaires on how to improve school sex education content were prepared, by which 207 male and female teachers were surveyed in the city of Paju and Koyang, Kyonggi province. The conclusions were as follows; 1. Content Analysis of Textbook Sex Education The content related to sex education was relatively much included in textbooks of the right life, morality and physical education. Although morality was a subject to be instructed for the third-grade students or older, elementary school students virtually received sex education from the first grade, as the right life and the joyful life were a subject for the lower-grade students, and this met the goal of sex education or the need of the times. However, sex education content leaned heavily toward family, family life or parental love. There was no mutual complement among subjects, and no link among grades, either. 2. Teacher Opinion on Sex Education Content for Each Grade When the subjects were asked about if sex education content was appropriate for each grade, they answered 20 items should be more emphasized and 6 items might be left out. And there were 6 items regarded by them as one that should be rearranged in consideration of grade. 3. The Ideal Opinion of Sex Education Content The following model could be recommended for elementary school sex education, which was designed to meet the objectives of school sex education as much as possible and to offer a systematic link among grades, based on the findings by textbook analysis and Questionnaire survey, and on elementary school sex education materials recommended by the Ministry of Education: The content selected for the first grade of elementary school was my body, cleanness of genitals, male-female cooperation, and family cooperation. For the second grade, the selected content was male-female physical difference, male female psychological difference, parental and I(origin of a birth). For the third grade, the selected things were important a body(cleanness of genitals), birth of a life, and male-female comprehension and cooperation. For the fourth grade, the selected things were physical development, management of genitals, physiology and management of menstruation, propagation and growth of organism, concern for the other sex, comprehension of and cooperation with the other sex, and prevention of sexual violence. Four the fifth grade, the selected things were secondary sex characteristic, physiology and management of menstruation, operation for phimosis, understanding of seminal emission, structure and function of the genital organs, birth and growth of a baby, television/sex information, and mass communications/sex information. For the sixth grade, the selected things were secondary sex characteristic, understanding of seminal emission, male-female cooperation, male and female role, male-female manners, mass communications/sex information, family and family life. Finally, what should be taught in sex education must be studied constantly, as it should be revised or supplemented periodically, according to student's sexual maturity or social, cultural changes.

• Communications of Mathematical Education
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• v.23 no.3
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• pp.735-760
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• 2009

Most of every teachers' life is occupied with his or her instruction, and a classroom is a laboratory for mutual development between teacher and students also. Namely, a teacher's professionalism can be enhanced by circulations of continual reflection, experiment, verification in the laboratory. Professional development is pursued primarily through teachers' reflective practices, especially instruction practices which is grounded on $Sch\ddot{o}n's$ epistemology of practices. And a thorough penetration about situations or realities and an exact understanding about students that are now being faced are foundations of reflective practices. In this study, at first, we explored the implications of earlier studies for discussing a teacher's practice. We could found two essential consequences through reviewing existing studies about classroom and instructions. One is a calling upon transition of perspectives about instruction, and the other is a suggestion of necessity of a teachers' reflective practices. Subsequently, we will talking about an instance of a middle school mathematics teacher's practices. We observed her instructions for a year. She has created her own practical knowledges through circulation of reflection and practices over the years. In her classroom, there were three mutual interaction structures included in a rich expressive environments. The first one is students' thinking and justifying in their seats. The second is a student's explaining at his or her feet. The last is a student's coming out to solve and explain problem. The main substances of her practical know ledges are creating of interaction structures and facilitating students' spontaneous changes. And the endeavor and experiment for diagnosing trouble and finding alternative when she came across an obstacles are also main elements of her practical knowledges Now, we can interpret her process of creating practical knowledge as a process of self-directed professional development when the fact that reflection and practices are the kernel of a teacher's professional development is taken into account.

• The Journal of Society for e-Business Studies
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• v.20 no.1
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• pp.23-43
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• 2015

Information and communications technology facilitates collaboration among individuals by functioning as an open platform for open collaboration projects. In this regard, this study aims to understand the network characteristics of participants who contribute greatly to open collaboration by investigating the mutual cooperation network in an open source project, which represents a form of open collaboration based on social network theory. To achieve this objective, this study analyzes the network centrality of developers with a high number of commits, particularly 8,101 developers in 782 repositories in GitHub, a representative open source platform. This study also determines how the relationship between network centrality and number of commits depends on the size of a repository network and the presence of a hub. Consequently, the number of commits by developers with high degree, betweenness, and closeness centrality is increasing. Among which, betweenness centrality has the highest explanatory power. Furthermore, when a hub is present and as network size increases, the relationship between the betweenness centrality of a developer and his/her number of commits continues to grow. This study is expected to provide suggestions for the successful performance of open collaboration projects in the future.

• Archives of design research
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• v.15 no.4
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• pp.1-14
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• 2002

In the past, companies concentrated their efforts on developing new technologies and producing new products. But new technologies in this information age do not make difference any more comparing to other companies. In this marketing environment, a company must appeal strongly their own image to the customers' brains to make better difference than other companies do. One of the best way to make their own image in the customer's brains might be outgrowing themselves of the one-way communication such as the printed-media or broadcast-media and preparing some space such as advertisement halls or pavilions where customers and companies meet each other and make mutual communications between both of them. Therefore, we need to study systematically on the design elements in the advertisement halls or pavilions. To begin with, we should lully understand the basic idea by looking up the reference literature. We case-studied on the basic of constructive elements of advertise halls of both SAMSUNG and LG Electronics Co. The purpose of this study is to realize that we can transfer effectively the company's image to the customers only if we fully understand company's business philosophy and vision in advance to start design the advertisement hails. We should also realize that it is also important to manage systematically the company's design strategic elements' to achieve its changing goals in more logical and scientifically way.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.12
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• pp.944-953
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• 2013

Recently, a storage media is becoming smaller and storage capacity is also becoming larger than before. However, important data was leaked through a small storage media. To solve these serious problem, many security companies manufacture secure USBs with secure function, such as data encryption, user authentication, not copying data, and management system for secure USB, etc. But various attacks, such as extracting flash memory from USBs, password hacking or memory dump, and bypassing fingerprint authentication, have appeared. Therefore, security techniques related to secure USBs have to concern many threats for them. The basic components for a secure USB are secure authentication and data encryption techniques. Though existing secure USBs applied password based user authentication, it is necessary to develop more secure authentication because many threats have appeared. And encryption chipsets are used for data encryption however we also concern key managements. Therefore, this paper suggests mutual device authentication based on PUF (Physical Unclonable Function) between USBs and the authentication server and key management without storing the secret key. Moreover, secure USB is systematically managed with metadata and authentication information stored in authentication server.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.11
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• pp.1094-1103
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• 2012

Recently, software industry regarding national defense increases system development of distributed simulation system of M&S based to overcome limit of resource and expense. It is one of key technologies for offering of mutual validation among objects and reuse of objects which are discussed for developing these systems. RTI, implementation of HLA interface specification as software providing these technologies uses Federation Object Model for exchanging information with joined federates in the federation and each federate has a characteristic that is supposed to have identical FOM in the federation. This technology is a software which is to provide the core technology which was suggested by the United state's military M&S standard framework. Simulator, virtual simulation, and inter-connection between military weapons system S/W which executes on network which is M&S's core base technology, and it is a technology which also can be used for various inter-connection between S/W such as game and on-line phone. These days although RTI is used in military war game or tactical training unit field, there is none in Korea. Also, it is used in mobile-game, distribution game, net management, robot field, and other civilian field, but the number of examples are so small and informalized. Through this developing project, we developed the core technique and RTI software and provided performance of COTS level to improve communication algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8C
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• pp.742-749
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• 2009

In this paper, we propose mitigation techniques using time-domain shortening filter (TSF) and frequency-domain shortening filter (FSF) to overcome inter-block interference (IBn and inter-carrier interference (ICn due to the time difference of arrival (TDoA) and carrier frequency offset (CFO) between downlink and uplink signals from access point (AP) and subscriber station (SS) in synchronous digital duplexing (SDD)/orthogonal frequency division multiple access (OFDMA) systems for indoor wireless communication. The proposed TSF and FSF maximize SIR for shortening in time (SIRST) and SINR for shortening in frequency (SINRSF), respectively, by using channel impulse responses and timing information among stations, obtained from mutual ranging procedure. It is verified by computer simulation that the proposed TSF and FSF reduce effectively the effects of IBI and ICI in the SDD/OFDMA systems.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.6
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• pp.699-711
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• 2003

Home networking and Internet control technologies must satisfy three requirements with a view to being applied to home for raising the qualify of human life. Firstly, the cost of adding home networking ability to the traditional appliance must be minimized. Secondly, the mutual accessibility between home network and Internet must be guaranteed in the various Internet service environment of home. Finally, communication must be possible between the home network and the Internet that use different communications protocols. This paper proposes the ARCS (Appliance Remote Control System) that controls appliances based on LnCP (Living network Control Protocol) via the Internet. LnCP is the most cost-effective network and control protocol for home network. ARCS guarantees the accessibility from the Internet to home network and provides users with the virtual interface designed for controlling appliances using the Internet application program. In addition, this paper proposes AICS (Appliance Internet Control Specification). AICS, is based on LnCP, defines the message structure and control commands for the Internet control communication. ARCS and home gateway are developed to meet AICS.